An efficient method for the preparation of N,N-disubstituted 1,2-diamines

C-2-Symmetric 12-diamines are useful precursors to numerous reagents used i n asymmetric synthesis and catalysis. We report here an efficient protocol for converting the two most commonly used trans-1,2-diamines to N,N-disubst ituted derivatives, a transformation that simplifies the preparation of non -C-2-symmetric diamines. central to the method is the high-yielding convers ion of the diamines to the corresponding monoacetylated derivatives via imi dazoline intermediates. (C) 2000 Published by Elsevier Science Ltd.